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So i have a 2007 mini cooper non s with 80,000 miles. I have developed a water leak that loses approx 20 ounces of water per day. I have located the leak but not sure what the hose is. Its located under the car. Behind the engine compartmentjn the center of the car. Its a hose that is almost smahed flat and just sticks out from between the floor pan and the heat sheilding and noise suppression material. I presume its a floor drain for the cabin?? I checked my new heater core that i installed months ago and it is not leaking. Is there anything else that would be leaking??
yeah that's what I thought. I believe the new replacement heater core that I installed a few months ago is now leaking. I did not buy the dealer part but a different brand off the ebay. I guess I'm paying the penalty now. Atleast it is a farily simple project.
I will get under it again tonight and double check it. but im almost positive it is coolant. I have to refill the reservoir bottle everynight after I get home from work. I have no other coolant leaks on the motor, I have looked it over closely. I didn't use the AC yesterday and when I had the car up and looking at that drain hose there was water coming out of it. I should have had the car running while looking at it but I didn't. and I didn't smell the liquid. I will do a better job tonight with the diagnoses and repost what I found. I did remove the trim panel by the heater core and made sure the inlet and outlet pipes weren't leaking, and they were fine. its probably the tank on the opposite end of the heater core.
Its coming out of the drain hose. so its operating as designed. Thanks everyone for all your help. I will be able to tell pretty quickly if its coolant or just water from the AC. But again, I wont be using the AC today.
so, after more investigating this weekend this is what I have found. The water coming out of that hose is only AC condensation and nothing else. The heater core is not leaking. inspecting the under side of the motor are I noticed that the water pump has crusty hardened water/antifreeze residue. So the water pump is seeping some. I replaced the water pump at 72,000 miles and now at 82,000 it seems as if I have the water pump starting to leak again, however, it is only slight and I can only tell its leaking by the crusty residue. in fact the crusty residue is hard and dry. there is no visible drip and wetness around the pump. ran the car for hours on Saturday then parked in driveway and continued to let it run. No water on ground, but the water reservoir did go down some. (about half/ 16ounces) let cool and refilled reservoir. so then I looked at dipstick again. still no water in oil. I then opened the oil fill cap and that is where is saw a problem (I think) inside the cap there was a brownish sludge. it appeared to me to be a water/oil mixture. I thought the worst so I drained the oil. The oil was perfect. Oil color was normal and there was no water at all in it. I also removed the oil filter. Same there. No water or any signs of water. So I did a coolant flush. No oil in the coolant. refilled the coolant with a proper antifreeze mix. also refilled oil with new filter. Purged coolant system as best as possible. Drove into work this morning and reservoir is down about 12ounces or so. I'm hoping it was just a little low on coolant and that when I refill all will be fine. I will know later tonight.
Any thoughts on the brown sludge in oil cap? I should have snapped a pic. I forgot.... Am I dealing with maybe a slight crack in the head and only water entering head??? again no white smoke out the pipe. Car runs perfect. No hesitations or missing and no engine lights or codes of any type.
If you don't have a pressure bleeder for the cooling system it is hard to get large bubbles out on the first couple of heat cycles, so a drop of coolant level in the tank isn't unnatural.
Brown color to the oil cap is not uncommon either, and in cooler temps you can get a milky film built up that is merely condensation and nothing more malignant.
The leak you have from the AC drain is just condensation, much like leaving a glass of ice water out in the heat; you are leaving a cold AC evaporator in a hot car.
I wouldn't sweat about anything going on right now as it all seems normal. If you are noticing the coolant dropping consistently, or are seeing leaks then you are okay to worry.
